This diploma thesis shows two basic basis, on which the accounting system may be established -- accrual basis and cash basis. The thesis focuses mainly on differences between these two basis, shown on the case of the Czech republic. Both two basis are explained and described, as well as their modifications and the Czech legislature and the International Financial Reporting Standards. Subjects using the accrual basis and the cash basis in the Czech republic are also shown. The thesis deals with specific items, which can figure only in accounting system based on accrual basis. These items conclude depreciation, asset provisions, reserves and deferred tax. The end of the thesis is dedicated to the confrontation of the two basis on the Cash flow statement. This Cash flow statement is based on the cash basis, while it is being used on the accrual basis.

The theoretical part is focused on the definition of the basic concepts of the assets, cash and accrual bases. In addition to profit, its components and its differences from the tax base. Much of the work deals with different concepts of costs and revenues in accordance with accounting regulations and tax law. The work deals with the various costs and revenues in terms of tax efficiency and impact on adjustments to the tax base.The practical part is devoted to empirical research, the proportion of tax on profit for the sampled companies.

The diploma work put brain to income from operations of natural persons in the accounting and tax evidence. At first it targets the income from operations and its different concept in the evidences. It describes establishment of income from operations on accrual and cash basis, defines components of income from operations - expenses, revenues, gains, losses, incomes and expenditures. The next part of the work focuses on legislation of income from operations in teh Czech Republic (in accounting and tax evidence).One of the chapters speeks about some economic transactions, which influences income from operations different in the accounting and tax evidence. The diploma work is finished with short example, which brings near the problem.

The topic of this thesis is issue of profit or loss in a company. First, we discuss a theoretical ways of defining and measuring profit or loss. In addition, attention will focus on the profit and loss statement and analysis of some of its items. Part of the thesis also deals with the taxation and profit distribution in the various business entities. In conclusion, the thesis analyzes profit or loss in a particular company.